1. Field of the Invention
The present invention relates generally to blender apparatus, and more particularly, but not by way of limitation, to a blender apparatus for blending fluids to be pumped down an oil or gas well.
2. Description of the Prior Art
Many activities conducted in connection with the servicing of oil or gas wells involve the blending of one or more solid particulate materials with a liquid which is to be pumped down into a well. One example is the blending of sand with a water base fluid for use in the hydraulic fracturing of a well.
A relatively recent development in blending technology by the assignee of the present invention is the constant level additive metering system disclosed in U.S. Pat. No. 4,490,047 to Stegemoeller et al. The Stegemoeller et al. '047 system utilizes a single pump to both draw base fluid from a fluid supply and draw blended fluid from a relatively small capacity blender. A portion of the fluid is then recirculated back to the blender, while a second portion is discharged to high pressure pumps which pump the blended fluid down into a well.